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3  TOMLAB /GP Solver Reference

A detailed description of the TOMLAB /GP solver interface is given below. Also see the M-file help for coplgpTL.m.

3.1  coplgpTL

Purpose
Solve geometric programming problems as described by equation 7 and below.
Calling Syntax
Prob = gpAssign( ... );
Result = tomRun('GP',Prob,...)

Prob	Problem description structure. The following fields are used:
GP.A	Linear constraint matrix for dual problem.
GP.coef	Posynomial coefficient vector.
GP.nterm	Number of terms in objective and constraints.
GP.moremem	Extra memory to allocate. Default 300*n + 300*m, where n is the total number of terms and m is the number of variables. If this is not enough the interface will double the memory until it is enough and try to solve it. The final value of moremem will be returned in Result.GP.lackmem. If you solve many similar problems in a sequence, set Prob.GP.moremem to Result.GP.lackmem in order to avoid many unnecessary memory allocations.
PriLevOpt	Print level in the solver. See GP.options.PRILEV.
GP	Structure with GP solver specific fields.
PrintFile	Name of file to print progress information and results to. The output written to file is always with a print level of 2. Default: Empty, none that is.
GP.options	Structure with special fields for the GP solver:
PRILEV	Print level of GP solver. Has precedence over Prob.PriLevOpt.
	==0 silent
	>=1 normal output with iteration log
	>=2 more verbose output
	>=10 memory debug output
	>=100 extreme debug output
	Default: 0
ITLM	Iteration limit.
	Default: 100
TOLX	Zero tolerance on the dual variables.
	Default: 1e-14
TOLZ	Zero tolerance on the constraint values.
	Default: 1e-14
EPSP	Feasibility tolerance on primal problem.
	Default: 1e-6
EPSD	Feasibility tolerance on dual problem.
	Default: 1e-6
EPSC	Feasibility tolerance on the linear dual constraints.
	Default: 1e-9
TOLPIV	Pivoting zero tolerance.
	Default: 1e-14
FRAC	Fractional decrease of steplength.
	Default: 0.9995
BIG	Value to treat as infinite.
	Default: 1e20

Description of Outputs

Result	Structure with result from optimization. The following fields are set:
	f_k	Function value at optimum.
	x_k	Optimal point.
	xState	State of each variable: 0/1/2/3: free / on lower bnd / on upper bnd / fixed.
	ExitFlag	Exit status. The following values are used:
	0:	Optimal solution found.
	1:	Maximum number of iterations reached.
	2:	(Possibly) unbounded problem.
	4:	(Possibly) infeasible problem.
	ExitText	The exit text according to Inform.
	Inform	Status value returned from the GP solver.
	0:	Optimal: find an optimal solution.
	1:	Unbounded: the reformulated problem is unbounded.
	2:	Infeasible: the reformulated problem is infeasible.
	3:	Iteration limit: reach the iteration limit before desired accuracy.
	4:	Numerical difficulties: encounter numerical problems.
	5:	Primal or dual infeasible: the original problems are infeasible.
	6:	Insufficient space: memory space is not sufficient.
	7:	Data file error: find input data errors.
	Solver	Name of the solver (GP).
	SolverAlgorithm	Description of the solver.
	GP.lackmem	See description for input Prob.GP.moremem.

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